import { Router } from 'express';
import { AuthManager } from '../auth/index.ts';
import { fetchGraph } from '../utils/index.ts';
import { acquireAppToken } from '../helper/msal.ts';

export default (auth?: AuthManager) => {
  const router = Router();

  router.get('/', async (req, res) => {
    try {
      let token: string;
      try {
        token = await acquireAppToken(req, auth);
      } catch (err: any) {
        return res.status(401).json({ error: 'Failed to acquire access token', message: err?.message ?? String(err) });
      }

      // Accept both camelCase and lowercase query parameter names
      const start = (req.query.startDateTime ?? req.query.startdatetime ?? req.query.start) as string;
      const end = (req.query.endDateTime ?? req.query.enddatetime ?? req.query.end) as string;

      if (!start || !end) {
        return res.status(400).json({
          error: 'Missing required query parameters: startDateTime and endDateTime',
        });
      }

      console.log(`📅 Fetching calendar view from ${start} to ${end}`);

      // token is acquired above

      // Build the endpoint with query parameters
      // Graph expects `startDateTime` / `endDateTime` casing in the query
      const endpoint = `/me/calendarview?startDateTime=${encodeURIComponent(
        start
      )}&endDateTime=${encodeURIComponent(end)}`;

      const calendarData = await fetchGraph(endpoint, token);

      res.json(calendarData);
    } catch (err: any) {
      console.error('Calendar view error:', err.message);
      res.status(500).json({ error: err.message });
    }
  });

  return router;
};